Camshaft governor



June 14, 1938. W Rl lSAKSON 2,120,612

CAMS HAFT GOVERNOR Filed April 3, 1936 3 Sheets-Sheet 1 QD K Q` (m Q \O W W I n Q l ff 4 IU l /J Q O\ l Z4 Zz? m V 7 .f i l f ff 5f-fz' Q O y ff ff ff. "24

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CAMSHAFT GOVERNOR Filed April 3, 1936 3 Sheets-Sheet 3 Zd ZI [nvenlor By'Q/mmw Patented June 14, 1938 yUNITED STATES PATENT oFFlcE 2 Claims.

The present invention relates to new and useful improvements in governors for the cam shafts of internal combustion engines and has for its primary object to provide, in a manner as here- 5 lnafter set forth, means operable by centrifugal force for automatically advancing the cam shaft as the speed of the engine increases.

Other objects of the invention are to provide a mechanism ofg'theaforementioned character which will be comparatively simple in construction, strong, durable, highly efli'cient and reliable in use, compact, light in weight and which may be manufactured and installed at low cost.

All of the foregoing and still further objects and advantages of the invention will become apparent from a study of the following specification', taken in connection with the accompanying drawings' wherein like characters of reference designate corresponding parts throughout the 20 several views, and wherein:-

Figure 1 is a view in front elevation of the head which is mounted thereon, the key forl locking said head to said cam shaft, the elements being shown separated, a portion of the cam shaft gear also being shown and broken away in section.

Figure 7 is a, view in end elevation of the cam shaft.

Figure 8 is a detail view in perspective of the polygonal head which is fixed on the end of the cam shaft. v

Figure 9 is a perspective view of one of the levers and one of the weights mounted thereon, the elements being shown separated.

Figure 10 is a view in side elevation of an arrangement which is used for mounting the speed responsive mechanism on cam shafts which are already in use, a portionl of the cam shaft gear being shown in vertical section.

Referring now to the drawings in detail, it will be seen that the reference numeral I designates the cam shaft of an internal combustion engine 2. Journalled on the forward end portion of the cam shaft I is a gear 3. It will be noted that the forward end of the cam shaft I projects beyond the gear 3 and formed therein is a diametrically extending groove 4. Formed centrally in the forward end of the cam shaft I isa threaded socket 5. An endless chain 6 drives the cam shaft gear 3 in the usual manner from a gear I on the engine crank shaft 8.

The reference numeral 9 designates an elongated head which is secured on the forward end of the cam shaft I by a cap screw I0. The head 9 has formed therein a centrally located opening II for the passage of the cap screw I0, said cap screw being threadedly engaged in the socket 5 of the cam shaft I. The head 9 has formed in its inner face a longitudinal groove I2 for the reception of locking keys I3 on opposite sides of the cap screw I0, which keys are also engaged in the groove 4 of the cam shaft I. It will be noted that the-socket 5 intersects the groove 4 and the opening II intersects the groove I2.

Pivot screws I3 are threadedly mounted in the gear 3 on opposite sides of the elongated head 9 and secured by locknuts I4. Journalled adjacent their inner ends on the pivots I 3' are levers I5 which, as best seen in Figure 3 of the drawings are provided with removable bushings I6, The levers I5 include bevelled inner end portions I1 through which adjustable contact screws I8 are threaded for engagement with the head 9. The screws I8 are secured inadjusted position by lock nuts I9. The outer end portions of the levers I5 have formed therein slots 20 which accommodate cap screws 2| which are threadedly mounted in the cam shaft gear 3. Lock nuts 22 (see Figure 5) are provided for the screws 2|. It may be well to here state that the screws 2I constitute stops for limiting the swinging movement of the levers I5. Mounted on the outer. end portions of the levers I5 are weights 23 which are secured in position by bolts 24 and nuts 25.

Reference numeral 26 designates a brace which extends between the pivot screws I3' of the levers I5, said brace being mounted on said screws between the heads thereof and said levers I5. Washers 21 are interposed between the brace 26 and the levers l5.

The operation of the invention is substantially as follows:

With the speed responsive mechanism in the position shown in Figure 2 of the drawings, the cam shaft I of the engine is in its normal position with respect to the engine valves, timer, etc. The elements remain in this position while the engine is idling or running at comparatively slow speed. However, when the engine is speeded up the levers I with the weights 23 thereon are swung outwardly by centrifugal force on the pivots I3 in a manner to advance the cam shaft I in angular relation relative to the gear 3 through the medium of the head 9 with which the contact screws I8 on the inner ends of the levers I5 are engaged. Of course, as the speed of the engine decreases, the cam shaft I, under the influence of the usual valve springs of the engine, returns to normal position relative to the gear 3. The brace 26 supports the pivot screws I3' at their outer ends against outward strain exerted thereon by the weighted levers I5. Through the medium of the screws I8 the levers I5 may be conveniently equahzed, also, the actuation of the cam shaft I by said levers may be regulated as desired.

The reference numeral 21 designates a casing for the gears 3 and 1, the endless chain 6, the speed responsive elements on said gear 3, etc. The casing 21' has a circular opening 28 formed therein which accommodates the speed responsive elements on the gear 3 and through the medium of which access to said elements may be conveniently had. A removable cover 29 is provided for the opening 28, said cover constituting an extension for the casing 21 which accommodates the speed responsive elements. A suitable gasket (not shown) is to be provided between the removable cover 29 and the casing 21.

The arrangement illustrated in Figure 10 of the drawings is for adapting the invention to engines which are already in use. 'In this embodiment an extension 30 is provided on the forward end of the cam shaft I which, it will be noted, is necessitated by the fact that said cam shaft does not project forwardly beyond the gear l. Keys 3I lock the extension 30 to the cam shaft I for rotation therewith. 'Ihe head 9 is mounted on the outer end of the extension 30, the keys I3 being engaged in a groove 32 which is provided therefor in the outer end of said extension. The extension 30 is provided with a centrally located opening (not shown) for the passage of the cap screw I0 which secures the elements 9, I3, 30,

and 3|, in assembled position on the cam shaft I. If desired, the keys Il and 3| may be Welded in position.

It is believed that the many advantages of a cam shaft governor constructed in accordance with the present invention will be readily understood and although preferred embodiments of the device are as illustrated and described, it is to be understood that changes in the details of construction and in the combination and arrangement of parts may be resorted to which will fall within the scope of the invention as claimed.

What is claimed is:-

1. A cam shaft, a gear journalled on said cam shaft, an elongated head xed on the cam shaft, pivots projecting from the gear on opposite sides of said head, levers `iournalled, at an intermediate point, on said pivots, a brace connecting the outer end portions of said pivots. contact screws adjustably mounted in one end portion of the levers and engaged with opposite sides of the head on opposite sides of the axis of said head, weights mounted on the other end portions ofthe levers for actuating said levers by centrifugal force and for advancing the cam shaft angularly relative to the gears, and means mounted on the gear for limiting the swinging movement of said levers.

2. A cam shaft, a gear journalled on said cam shaft, an elongated head fixed on the cam shaft, pivots projecting from the gear on opposite sides of said head, levers journalled, at an intermediate point, on said pivots, a brace connecting the outer end portions of said pivots, contact screws adjustably mounted in one end portion of the levers and engaged with opposite sides of the head on opposite sides of the axis of said head, weights mounted on the other end portions of the levers for actuating said levers by centrifugal force and for advancing the cam shaft angularly relative to the gears, and means mounted onthe gear for limiting the swinging movement of said levers, said means including bolts threaded into the gear, the levers having slots in said other end portions thereof in which said bolts are engaged.

WALTER R. ISAKSON. 

